The data in question was gathered using an app called thisisyourdigitallife, created by Kogan, that offered Facebook users personality quizzes. Those who downloaded the app voluntarily turned over reams of personal data about what they like, where they live, and in some cases, depending on individual privacy settings, who their friends were. Though Facebook says just 270,000 people downloaded the app, a loophole at the time apparently allowed Kogan to collect vastly more information. Until 2014, apps could also collect information on every users' entire friend network. Facebook shut down that capability for app developers in mid-2014, but offered some apps that were already up and running a small grace period before cutting them off. That timing roughly lines up with Kogan's research. Of the 50 million accounts Kogan had data on, the New York Times and Guardian reports say, 30 million had complete enough profiles that Cambridge could create psychographic profiles of them. Different than demographic profiles, these describe people based on their personality types.